diff --git a/dotnet/AipsCore/AipsCore.csproj b/dotnet/AipsCore/AipsCore.csproj
index 0124700..d062ba1 100644
--- a/dotnet/AipsCore/AipsCore.csproj
+++ b/dotnet/AipsCore/AipsCore.csproj
@@ -17,6 +17,7 @@
     </ItemGroup>
 
     <ItemGroup>
+      <Folder Include="Domain\Models\WhiteboardMembership\Validation\" />
       <Folder Include="Infrastructure\Persistence\Db\Migrations\" />
     </ItemGroup>
 
diff --git a/dotnet/AipsCore/Domain/Common/Validation/Rules/DateInFutureRule.cs b/dotnet/AipsCore/Domain/Common/Validation/Rules/DateInFutureRule.cs
new file mode 100644
index 0000000..cf48254
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Common/Validation/Rules/DateInFutureRule.cs
@@ -0,0 +1,22 @@
+using AipsCore.Domain.Abstract.Rule;
+
+namespace AipsCore.Domain.Common.Validation.Rules;
+
+public class DateInFutureRule : AbstractRule
+{
+    private readonly DateTime _date;
+    private readonly DateTime _now;
+    
+    public DateInFutureRule(DateTime date) 
+    {
+        _date = date;
+        _now = DateTime.Now;
+    }
+    
+    protected override string ErrorCode => "date_in_future";
+    protected override string ErrorMessage => "Date must be in the future";
+    public override bool Validate()
+    {
+        return _date > _now;
+    }
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Common/Validation/Rules/DateInPastRule.cs b/dotnet/AipsCore/Domain/Common/Validation/Rules/DateInPastRule.cs
new file mode 100644
index 0000000..2120aa6
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Common/Validation/Rules/DateInPastRule.cs
@@ -0,0 +1,22 @@
+using AipsCore.Domain.Abstract.Rule;
+
+namespace AipsCore.Domain.Common.Validation.Rules;
+
+public class DateInPastRule : AbstractRule
+{
+    private readonly DateTime _date;
+    private readonly DateTime _now;
+
+    public DateInPastRule(DateTime date) 
+    {
+        _date = date;
+        _now = DateTime.Now;
+    }
+    
+    protected override string ErrorCode => "date_in_past";
+    protected override string ErrorMessage => "Date must be in the past";
+    public override bool Validate()
+    {
+        return _date < _now;
+    }
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Models/WhiteboardMembership/External/IWhiteboardMembershipRepository.cs b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/External/IWhiteboardMembershipRepository.cs
new file mode 100644
index 0000000..2d70762
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/External/IWhiteboardMembershipRepository.cs
@@ -0,0 +1,9 @@
+using AipsCore.Domain.Models.WhiteboardMembership.ValueObjects;
+
+namespace AipsCore.Domain.Models.WhiteboardMembership.External;
+
+public interface IWhiteboardMembershipRepository
+{
+    Task<WhiteboardMembership?> Get(WhiteboardMembershipId whiteboardMembershipId, CancellationToken cancellationToken = default);
+    Task Save(WhiteboardMembership whiteboardMembership, CancellationToken cancellationToken = default);
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipCanJoin.cs b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipCanJoin.cs
new file mode 100644
index 0000000..48591ad
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipCanJoin.cs
@@ -0,0 +1,20 @@
+using AipsCore.Domain.Abstract.Rule;
+using AipsCore.Domain.Abstract.ValueObject;
+
+namespace AipsCore.Domain.Models.WhiteboardMembership.ValueObjects;
+
+public record WhiteboardMembershipCanJoin : AbstractValueObject
+{
+    public bool CanJoinValue { get; init; }
+
+    public WhiteboardMembershipCanJoin(bool CanJoinValue)
+    {
+        this.CanJoinValue = CanJoinValue;
+        Validate();
+    }
+    
+    protected override ICollection<IRule> GetValidationRules()
+    {
+        return [];
+    }
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipEditingEnabled.cs b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipEditingEnabled.cs
new file mode 100644
index 0000000..da674c1
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipEditingEnabled.cs
@@ -0,0 +1,20 @@
+using AipsCore.Domain.Abstract.Rule;
+using AipsCore.Domain.Abstract.ValueObject;
+
+namespace AipsCore.Domain.Models.WhiteboardMembership.ValueObjects;
+
+public record WhiteboardMembershipEditingEnabled : AbstractValueObject
+{
+    public bool EditingEnabledValue { get; init; }
+
+    public WhiteboardMembershipEditingEnabled(bool EditingEnabledValue)
+    {
+        this.EditingEnabledValue = EditingEnabledValue;
+        Validate();
+    }
+    
+    protected override ICollection<IRule> GetValidationRules()
+    {
+        return [];
+    }
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipId.cs b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipId.cs
new file mode 100644
index 0000000..4f786e0
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipId.cs
@@ -0,0 +1,8 @@
+using AipsCore.Domain.Common.ValueObjects;
+
+namespace AipsCore.Domain.Models.WhiteboardMembership.ValueObjects;
+
+public record WhiteboardMembershipId(string IdValue) : DomainId(IdValue)
+{
+    public static WhiteboardMembershipId Any() => new(Guid.NewGuid().ToString());
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipIsBanned.cs b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipIsBanned.cs
new file mode 100644
index 0000000..363e9ab
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipIsBanned.cs
@@ -0,0 +1,20 @@
+using AipsCore.Domain.Abstract.Rule;
+using AipsCore.Domain.Abstract.ValueObject;
+
+namespace AipsCore.Domain.Models.WhiteboardMembership.ValueObjects;
+
+public record WhiteboardMembershipIsBanned : AbstractValueObject
+{
+    public bool IsBannedValue { get; init; }
+
+    public WhiteboardMembershipIsBanned(bool IsBannedValue)
+    {
+        this.IsBannedValue = IsBannedValue;
+        Validate();
+    }
+    
+    protected override ICollection<IRule> GetValidationRules()
+    {
+        return [];
+    }
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipLastInteractedAt.cs b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipLastInteractedAt.cs
new file mode 100644
index 0000000..b9b8952
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/ValueObjects/WhiteboardMembershipLastInteractedAt.cs
@@ -0,0 +1,23 @@
+using AipsCore.Domain.Abstract.Rule;
+using AipsCore.Domain.Abstract.ValueObject;
+using AipsCore.Domain.Common.Validation.Rules;
+
+namespace AipsCore.Domain.Models.WhiteboardMembership.ValueObjects;
+
+public record WhiteboardMembershipLastInteractedAt : AbstractValueObject
+{
+    public DateTime LastInteractedAtValue { get; init; }
+
+    public WhiteboardMembershipLastInteractedAt(DateTime LastInteractedAtValue)
+    {
+        this.LastInteractedAtValue = LastInteractedAtValue;
+        Validate();
+    }
+    
+    protected override ICollection<IRule> GetValidationRules()
+    {
+        return [
+            new DateInPastRule(LastInteractedAtValue)
+        ];
+    }
+}
\ No newline at end of file
diff --git a/dotnet/AipsCore/Domain/Models/WhiteboardMembership/WhiteboardMembership.cs b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/WhiteboardMembership.cs
new file mode 100644
index 0000000..6cd006f
--- /dev/null
+++ b/dotnet/AipsCore/Domain/Models/WhiteboardMembership/WhiteboardMembership.cs
@@ -0,0 +1,105 @@
+using AipsCore.Domain.Models.User.ValueObjects;
+using AipsCore.Domain.Models.Whiteboard.ValueObjects;
+using AipsCore.Domain.Models.WhiteboardMembership.ValueObjects;
+
+namespace AipsCore.Domain.Models.WhiteboardMembership;
+
+public class WhiteboardMembership
+{
+    public WhiteboardMembershipId Id { get; private set; }
+    public WhiteboardId WhiteboardId { get; private set; }
+    public UserId UserId { get; private set; }
+    public WhiteboardMembershipIsBanned IsBanned { get; private set; }
+    public WhiteboardMembershipEditingEnabled EditingEnabled { get; private set; }
+    public WhiteboardMembershipCanJoin CanJoin { get; private set; }
+    public WhiteboardMembershipLastInteractedAt LastInteractedAt { get; private set; }
+
+    public WhiteboardMembership(
+        WhiteboardMembershipId id,
+        Whiteboard.Whiteboard owner, 
+        User.User user,
+        WhiteboardMembershipIsBanned isBanned,
+        WhiteboardMembershipEditingEnabled editingEnabled,
+        WhiteboardMembershipCanJoin canJoin,
+        WhiteboardMembershipLastInteractedAt lastInteractedAt)
+    {
+        Id = id;
+        WhiteboardId = owner.Id;
+        UserId = user.Id;
+        IsBanned = isBanned;
+        EditingEnabled = editingEnabled;
+        CanJoin = canJoin;
+        LastInteractedAt = lastInteractedAt;
+    }
+    
+    public WhiteboardMembership(
+        WhiteboardMembershipId id,
+        WhiteboardId ownerId, 
+        UserId userId,
+        WhiteboardMembershipIsBanned isBanned,
+        WhiteboardMembershipEditingEnabled editingEnabled,
+        WhiteboardMembershipCanJoin canJoin,
+        WhiteboardMembershipLastInteractedAt lastInteractedAt)
+    {
+        Id = id;
+        WhiteboardId = ownerId;
+        UserId = userId;
+        IsBanned = isBanned;
+        EditingEnabled = editingEnabled;
+        CanJoin = canJoin;
+        LastInteractedAt = lastInteractedAt;
+    }
+    
+    public static WhiteboardMembership Create(
+        string id, 
+        string ownerId,
+        string userId,
+        bool isBanned,
+        bool editingEnabled,
+        bool canJoin,
+        DateTime lastInteractedAt)
+    {
+        var whiteboardMembershipId = new WhiteboardMembershipId(id);
+        var whiteboardId = new WhiteboardId(ownerId);
+        var userIdVo = new UserId(userId);
+        var isBannedVo = new WhiteboardMembershipIsBanned(isBanned);
+        var editingEnabledVo = new WhiteboardMembershipEditingEnabled(editingEnabled);
+        var canJoinVo = new WhiteboardMembershipCanJoin(canJoin);
+        var lastInteractedAtVo = new WhiteboardMembershipLastInteractedAt(lastInteractedAt);
+        
+        return new WhiteboardMembership(
+            whiteboardMembershipId, 
+            whiteboardId, 
+            userIdVo, 
+            isBannedVo, 
+            editingEnabledVo, 
+            canJoinVo, 
+            lastInteractedAtVo);
+    }
+    
+    public static WhiteboardMembership Create(
+        string ownerId,
+        string userId,
+        bool isBanned,
+        bool editingEnabled,
+        bool canJoin,
+        DateTime lastInteractedAt)
+    {
+        var whiteboardMembershipId = WhiteboardMembershipId.Any();
+        var whiteboardId = new WhiteboardId(ownerId);
+        var userIdVo = new UserId(userId);
+        var isBannedVo = new WhiteboardMembershipIsBanned(isBanned);
+        var editingEnabledVo = new WhiteboardMembershipEditingEnabled(editingEnabled);
+        var canJoinVo = new WhiteboardMembershipCanJoin(canJoin);
+        var lastInteractedAtVo = new WhiteboardMembershipLastInteractedAt(lastInteractedAt);
+        
+        return new WhiteboardMembership(
+            whiteboardMembershipId, 
+            whiteboardId, 
+            userIdVo, 
+            isBannedVo, 
+            editingEnabledVo, 
+            canJoinVo, 
+            lastInteractedAtVo);
+    }
+}
\ No newline at end of file